RESUMO
BACKGROUND: There are many collagen-stimulating fillers, including calcium hydroxyapatite, polycaprolactone (PCL), and poly-L-lactic acid (PLLA), and other materials have been tested. Polydioxanone (PDO) has recently been used as absorbable thread-lifting material due to its collagen-forming effects. PDO in powdered form is expected to be a good material for collagen-producing fillers. OBJECTIVES: To evaluate the collagen-producing effects of powdered PDO injection compared with PLLA injection in a murine model. MATERIALS AND METHODS: Powdered PDO mixed with sodium carboxymethyl cellulose, PLLA, and phosphate-buffered saline was injected on dorsal skin of 8-week-old rat. Tissue samples were obtained 1, 2, and 12 weeks after the procedures for histopathologic review and for real-time PCR to quantify collagen and tissue growth factors. RESULTS: Both PLLA and powdered PDO injections induced granulomatous reactions. Collagen type 1, collagen type 3, TGF-ß1, TGF-ß2, and TGF-ß3 showed increases 2 weeks after injection but decreased 12 weeks after injection for both powdered PDO and PLLA. CONCLUSION: Our results suggested that powdered PDO injection induces collagen formation more effectively than PLLA injection. Therefore, PDO can be a good option for forming collagen.